This application relates generally to gas turbine engines and, more particularly, to methods and apparatus for assembling gas turbine engine rotor assemblies.
At least some known gas turbine engines include a compressor for compressing air which is mixed with a fuel and channeled to a combustor wherein the mixture is ignited within a combustion chamber for generating hot combustion gases. The hot combustion gases are channeled downstream to a turbine, which extracts energy from the combustion gases for powering the compressor, as well as producing useful work to propel an aircraft in flight or to power a load, such as an electrical generator.
Known compressors include a rotor assembly that includes at least one row of circumferentially spaced rotor blades. Each rotor blade includes an airfoil that includes a pressure side, and a suction side connected together at leading and trailing edges. Each airfoil extends radially outward from a rotor blade platform. Each rotor blade also includes a dovetail that extends radially inward from the platform, and is used to mount the rotor blade within the rotor assembly to a rotor disk or spool. More specifically, at least some known rotor disks include a circumferential dovetail slot that is sized to receive the plurality of rotor blades therein.
Known rotor blade dovetails are generally shaped complementary to the disk dovetail slot to enable the rotor blade dovetails and the rotor disk slot to mate together and form a dovetail assembly. The blade dovetails each include at least one pair of tangs that extend to a substantially planar dovetail bottom extending between the dovetail tangs. The rotor blade dovetail tangs are received within corresponding disk slot tangs.
During operation, the rotor blade dovetails and the chamfered dovetail tangs may be subjected to compressive loading. More specifically, the compressive loading may cause bending stresses to be induced into the rotor blades from the dovetails. To facilitate reducing such bending stresses, at least some known rotor blades are fabricated to have tight tolerances defined between the rotor blade dovetail and the dovetail slot. However, because of space and weight considerations, not all rotor assemblies can be assembled within a respective gas turbine engine using axial dovetail slots.